Dyes have conventionally been used as a colorant of ink for inkjet recording. However, dye ink has the deficiency that it has less water resistant properties and less atmospheric corrosion resistance, so it easily blots on plain paper. In order to overcome these defects, pigment ink where pigment is used as a colorant has been proposed. Even though this pigment ink has excellent water resistant properties and atmospheric corrosion resistance and enables recording of images with less bleeding, there is the problem that it has less fixation.
Therefore, the improvement of the fixation by adding various resins has been attempted. For example, a method to record images with less bleeding by adding thermoplastic resin emulsion to pigment ink is proposed (refer to Patent Literature 1). However, in this proposal, because drying by heating is performed, there is the deficiency that the apparatus becomes complex and that there is more consumption of electricity.
Further, an ink composition where an acrylic silicone resin fine-particle containing an alkoxysilyl group is used (refer to Patent Literature 2) and a coating agent composed of reactivity resin emulsion having a hydrolyzable silyl group and an amine imide group (refer to Patent Literature 3) are proposed. However, these proposals do not take the improvement of fixation and storage properties into consideration, making them unsuitable for practical use.
Further, Patent Literature 4 proposes a method where the emulsion copolymerization of a vinyl monomer having a specific reactive silyl group, which exists in the form of a salt, another vinyl monomer having a reactive silyl group other than that mentioned above, and other vinyl monomer copolymerizable with these monomers results in the production of polymer emulsion while the hydrolyzable silyl group exists stably.
However, in this proposal, there is the deficiency that the resin fine-particle where the hydrolyzable silyl group remains reacts with the ink, and causes a decrease of the long-term storage properties of the ink.
Further, Patent Literature 5 proposes a recording liquid where emulsion resin, which is formed by the radical polymerization of an ethylene unsaturated monomer in the presence of a radical reactivity emulsion, and pigment is dispersed in a aqueous medium. However, with this proposal, there is no disclosure or suggestion regarding whether or not an alkoxysilyl group remains in the emulsion resin, and even though a left standing test for a dispersion of the emulsion resin, glycerin and water was conducted, since composition containing the emulsion resin, glycerin and water has high surface tension, it has less permeability to a recording medium. In addition, ink containing a resin component tends to have less permeability because the ink is easily accumulated on a recording medium after printing. If high-speed printing or high-speed double side printing is performed using ink with inferior permeability, there is the problem that a roller for the purpose of conveying a recording medium rubs the printed portion immediately after printing, and smearing occurs.
Further, Patent Literature 6 proposes a method where a polymeric monomer is emulsion-polymerized and an organosiloxane compound is absorbed into the obtained polymer particles and condensation occurs. In this proposal, the particles themselves form a film with excellent tolerance. However, in the ink containing the pigment, in order to fix the pigment and to add excellent abrasion resistance and marker resistance, it becomes necessary to add a large quantity of resin fine-particle. However, with ink containing a large quantity of resin, there is the problem that the ink dries out in the vicinity of a nozzle, which discharges the ink when printing, with the easy occurrence of droplet bend or no discharge.
Therefore, recording ink with excellent discharge stability and storage stability, which rapidly penetrates into a recording medium and forms a coating, and which will never generate smearing upon high-speed printing or double-sided printing, and which excels in marker resistance, and which enables high quality image recording with less bleeding, has not been provided yet, so the actual situation is that the prompt development of ink is desired.                Patent Literature 1 Japanese Patent Application Laid-Open (JP-A) No. 9-176533        Patent Literature 2 Japanese Patent (JP-B) No. 3011087        Patent Literature 3 Japanese Patent Application Laid-Open (JP-A) No. 5-25354        Patent Literature 4 Japanese Patent Application Laid-Open (JP-A) No. 6-157861        Patent Literature 5 Japanese Patent Application Laid-Open (JP-A) No. 2002-294105        Patent Literature 6 Japanese Patent Application Laid-Open (JP-A) No. 7-278480        